The square of sevens / Laura Shepherd-Robinson.

Enhanced descriptions from Syndetics:

This "intricately plotted, epic" ( The Times , London) international bestseller--in the vein of the vivid novels of Sarah Waters and Sarah Perry--follows an orphaned fortune teller in 18th-century England as she searches for answers about her long-dead mother.

Cornwall, 1730: A young girl known only as Red travels with her father making a living predicting fortunes using the ancient Cornish method of the Square of Sevens. Shortly before he dies, her father entrusts Red's care to a gentleman scholar, along with a document containing the secret of the Square of Sevens technique.

Raised as a lady amidst the Georgian splendor of Bath, Red's fortune telling delights in high society. But she cannot ignore the questions that gnaw at her soul: who was her mother? How did she die? And who are the mysterious enemies her father was always terrified would find him?

The pursuit of these mysteries takes her from Cornwall and Bath to London and Devon, from the rough ribaldry of the Bartholomew Fair to the grand houses of two of the most powerful families in England. And while Red's quest brings her the possibility of great reward, it also leads to grave danger.

"Intricate, haunting, and magical by turns, Laura Shepherd-Robinson's tale is an absolute immersive read you won't soon forget" (Patti Callahan Henry, New York Times bestselling author).